Because of the rapid distribution and metabolism clearance from kidney, high specificity to the FAP, and the high stability of the probe in vivo, the T/K ratios showed a consistent increase from 0.04 ± 0.01 (30 min p.i.)to 0.41 ± 0.06 ID%/g (after 90 min p. i.), and the corresponding tumor/muscle (T/M) ratios changed from 1.16 ± 0.25 to 4.74 ± 0.07. This evidence concerns the gene FAP and neoplasm.